(1) Summary
The present invention relates to a method for controlling weed grasses by infecting them with a Xanthomonas campestris pathovar which does not infect non-weed grasses. In particular the present invention relates to the use of Xanthomonas campestris NRRL-B-18078 to suppress or kill the weed grasses.
(2) Prior Art
Bacteria infect grasses causing the grasses to be suppressed or killed. These infections have been known in other parts of the world as important problems for the maintenance of desirable grasses. So far as the inventor is aware, the present invention is the first attempt to suppress or kill a weed grass by applying a weed suppressing pathovar of bacteria to the grass. This method . of biological control eliminates the need for herbicides which are relatively toxic chemicals to people and the environment.
A bacterial infection of Toronto creeping bentgrass which is used on golf putting greens is described by Roberts, D. L., et al in Plant Disease 65, 1014-1015 (1981); Roberts, D. L., et al, Plant Disease 66, 804-806 (1982); Roberts, D. L., et al, Scanning Electron Microscopy IV, 1719-1722 (1983). The bacterium was identified as a Xanthomonas campestris by Roberts, D. L. in Phytopathology 73, 810 and 74, 813 (1984). The solution to the problem was treatment of the infection with oxytetracycline, an antibiotic. A disease of Poa annua L. was also described by Roberts, D. L. In Phytopathology 75 1289 (1985).
The diseases caused by Xanthomonas campestris pathovars has also been studied by others and has been found to be selectively pathogenic to particular grass species. Egli T., et al Phytopath Z. 82, 111-121 (1975) first characterized a bacterial infection of cut grasses. Other publications include: Wilkins, P. W., et al, Plant Path 26, 99 (1977); DeCleene, M., et al., Parasitica 37(1) 29-34 (1981); Leyns, F., et al., Parasitica 37, 131-133 (1981); Van Den Mooter, M. et al, Med Fac Landbouww Rijksuniv. Gent 46/3, 787-792 (1981); Van Den Mooter, M., et al Parasitica 37 (1):23-28 (1981); Proc. Fifth Int. Conf. Path Bact, Calif 332-333 (1981); Egli, T. et al. Phytopath Z. 104, 138-150 (1982); and Leyns et al Med. Fac. Landbouww Rijksuniv Gent. 47/3 1079-1081 (1982).